Thursday, October 02, 2008

SOLX Titaniam-Sapphire Laser for Treating Glaucoma: A First Report

On September 18th, Solx Inc., a Boston-based spinout from Boston University's Photonics Center, now based in Waltham, MA, announced that it had received FDA 510(k) clearance for its SOLX 790 Titanium:Sapphire laser to perform laser trabeculoplasty (TLT).

The clearance was based on the results of a multicenter, international clinical trial that established equivalency of TLT to argon laser trabeculoplasty (ALT) in its ability to reduce IOP in patients who have primary open-angle glaucoma and have poorly controlled IOP on maximally tolerated medications, and/or who have prior failed trabeculoplasty.

The laser was previously approved for sale in Europe and Canada.

In the trial, which was conducted across the United States, Europe, Canada and Israel, more than 180 patients were randomized either for ALT or TLT. Results showed that patients at 12-month follow-up achieved a mean IOP reduction of 6.8 ± 4.7 mmHg (25.8 percent) for TLT vs. 5.7 ± 4.8 mmHg (22.2 percent) for ALT.

"Patients treated with the SOLX 790 laser achieved an immediate reduction in IOP which was maintained at clinically beneficial levels throughout the study," said Francisco Fantes, M.D., Bascom Palmer Eye Institute, Miami, Florida, and Medical Monitor for the trial. "TLT does so without causing significant thermal damage to the treated tissues which provides glaucoma specialists with an important new tool for managing this disease."

"This is a significant milestone for SOLX," said Doug Adams, President and founder of SOLX, "The SOLX 790 laser is the cornerstone of our glaucoma management system along with the SOLX Gold Shunt."

The SOLX 790 laser emits pulses of energy at a near-infrared 790 nm wavelength to loosen particles in the trabecular meshwork without causing significant thermal damage. The energy penetrates deeper into the tissue than other currently used trabeculoplasty lasers and may therefore lead to longer-lasting treatment benefits

The SOLX 790 Laser is a flashlamp-excited, solid-state laser that emits near-infrared light in pulses lasting five to 10 microseconds. The laser has been shown to provide deeper tissue penetration, about 200 microns, deeper, than the other lasers currently used in trabeculoplasty without causing damage to the trabecular meshwork.

The following graphics and illustrations were taken from the SOLX, Inc., 790 Laser website:

The SOLX 790 Laser
Technical Specifications

Approvals and Ongoing Trials

How it Works Compared to the Argon (ALT) and Doubled YAG (green) (SLT) Lasers

A Comparison of the Technical Specifications for the Three Laser Systems

The Thermal Effects Differences Between the Three Lasers

IOP Following SOLX 790 Laser TLT Treatment

Average Number of Medications Needed Following SOLX 790 TLT Treatment


Glaucoma is a disease of the eye in which damage is caused by elevated pressure within the eye. This elevated pressure is caused by a backup of fluid (aqueous humor) in the space/chamber between the cornea (the front surface of the eye), and the lens within the eye. Over time this pressure buildup causes damage to the optic nerve. Normal pressure in the eye varies between 10-20 mmHg.

There are several different types of glaucoma which are generally grouped in to two large categories: open-angle glaucoma and closed angle glaucoma.

Open-angle glaucoma: Glaucoma in which the aqueous (fluid) that flows through the cornea into the anterior (front) chamber of the eye cannot get through a filtration system called the trabecular meshwork into the drainage canals, causing pressure to build up within the eye which can damage the optic nerve and impair vision. Open-angle glaucoma is the most common form of glaucoma, and can be treated with the above types of lasers.

Closed angle glaucoma, (also called acute glaucoma or angle closure glaucoma), accounts for about 9 percent of all glaucoma cases and occurs when the opening between the cornea and iris narrows, such that the fluid cannot get to the trabecular meshwork and normal drainage channels. This narrowing results in fluid build-up and intraocular pressure. The fluid build-up happens very quickly.

I have previously written on the surgical and laser treatments for glaucoma. An overview can be found in my “Advances in the Treatment of Glaucoma”, done as an Optistock Industry Overview in the Fall of 2001. In addition, I have written extensively about another laser treatment for glaucoma, Selective Laser Trabeculoplasty (SLT) – SLT: New Treatment for Glaucoma Becomes Available , both in Ocular Surgery News (May 15, 2001) and an update on this laser methodology – An Update on the Use of SLT for Treating Glaucoma – in this Journal.


At 5:24 AM, Blogger Unknown said...

Your article is extremely valuable for the many claucoma patients !!

Can you follow up on this article and tell us where treatment is available with this new laser (in the US or elsewhere) or if there are any other new developments or data.

As far as I know there is a new study out, comparing ALT / SLT and this new Sapphire Laser. Can you elaborate?

Thank you,


At 11:14 AM, Blogger Irv Arons said...


I have contacted the president of SOLX Laser, and have asked him to respond to your comment. If he does, I will post it on this space.

Irv Arons

At 3:06 AM, Anonymous Anonymous said...

Hi Irv,

I am concerned about the fact that the deeper penetration of the 790 nm wavelength, coupled with the comparatively long pulse duration (8 microseconds vs. 3 NANO-seconds of SLT and/or 1 MICRO-second of MLT) may potentially rapture the endothelial wall of Schlemm's canal.

Secondly, the product footprint is unusually large (compared to any SLT, ALT or MLT product currently available in the market). Is this a prototype or the actual product?

What is your take on the above two thoughts?



At 11:24 AM, Blogger Irv Arons said...


Although I met with Doug Adams when he first started this project back at the B.U. Photonics Center, I have not spoken to him since.

I also have not seen any writeups about his device in the media, which was why I decided to post the story on my blog.

I have tried to contact Doug with questions several times, but as yet, have had no response.

I guess what I am trying to say is I don't have the knowledge to be able to answer your questions.

Irv Arons

At 2:26 PM, Anonymous Anonymous said...

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